Field of the Invention
The present invention relates to an image capturing apparatus, a control method of an image capturing apparatus, and a non-transitory computer readable storage medium.
Description of the Related Art
Image capturing apparatuses transform raw image information (RAW image) captured by an image sensor into signals including luminance signals and color difference signals. To each signal thus obtained, so-called development processing, which includes denoising, optical distortion correction, image optimization, etc. is applied, and the luminance signals and color difference signals that have undergone the development processing are compression-coded and recorded on a recording medium.
Some image capturing apparatuses, however, are capable of recording RAW images per se. Although RAW images have a vast amount of data to be recorded, they have the advantage of not being altered or degraded from the original image, and being editable after shooting. A configuration of an image capturing apparatus that records RAW images is disclosed in Japanese Patent Laid-Open No. 2011-244423. Japanese Patent Laid-Open No. 2011-244423 discloses a configuration for recording development parameters together with a RAW image, and then developing and playing back the RAW image by using the development parameters.
Assume a case where a continuous shooting is performed by an image capturing apparatus that is capable of storing a RAW image and a developed image (e.g. a JPEG image) generated by performing development processing on the RAW image onto a recording medium such as an SD card. While the apparatus is performing a continuous shooting (i.e., while the shutter button is kept being pressed), RAW image data is stored (i.e. buffered) into a temporary memory such as a DRAM buffer one after another. The RAW image data sequentially undergo development processing and compression processing and are transferred to and recorded on the recording medium, in the order they were buffered.
In this case, if the amount, per unit time, of the data buffered into the temporary memory during the continuous shooting is greater than the amount, per unit time, of the data that has undergone the development processing and compression processing on the temporary memory and then transferred to the recording medium, the storage space of the temporary memory will be fully occupied by the RAW image data. If the storage space of the temporary memory is fully occupied by the RAW image data, the speed of the buffering of the RAW image data generated by the continuous shooting will decrease to the speed of the development processing and the compression processing performed on the RAW image data on the temporary memory and the transferring and the storing of the data onto the recording medium. In other words such a situation results in degradation of the speed of continuous shooting performed by the image capturing apparatus.